fix(docs): remove white gap in homepage demo terminal (light mode)

[oekazuma]

Summary

Fixes a visual bug on the deployed homepage, reported after merging #296: in light mode, the demo terminal's dark title bar and dark GIF content had a jarring white gap between them.

Root cause: Blume's global stylesheet applies a default top/bottom margin to <img> elements. .demo-terminal has overflow: hidden and a transparent background, so that margin pushed the demo GIF down, exposing the transparent container's background (= page background) between the title bar and the image — invisible in dark mode (page background is also dark) but a visible white band in light mode.

Fix: reset margin: 0 and set display: block explicitly on .demo-terminal img in both index.mdx and ja/index.mdx.

Test plan

• Reproduced on the live production site by toggling to light mode via data-theme="light"
• Verified locally with blume dev that the gap is gone after the fix, in both light and dark mode
• pnpm lint passes
• Confirmed the dev-dashboard guide's .theme-img screenshots are unaffected (different container, no regression there)

🤖 Generated with Claude Code

Summary by CodeRabbit

• Style
  • Improved terminal demo image rendering on the documentation homepage.
  • Removed unwanted spacing and ensured images display consistently across English and Japanese pages.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro Plus

Run ID: 4b7227cf-6025-47d8-ba14-b44178b96c01

📥 Commits

Reviewing files that changed from the base of the PR and between 4cd41cb and 108a9e4.

📒 Files selected for processing (2)

• docs/src/content/docs/index.mdx
• docs/src/content/docs/ja/index.mdx

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📝 Walkthrough

Walkthrough

The documentation homepages for English and Japanese add display: block and margin: 0 to the terminal demo image styling.

Changes

Terminal Demo Styling

Layer / File(s)	Summary
Terminal image layout rules docs/src/content/docs/index.mdx, docs/src/content/docs/ja/index.mdx	The .demo-terminal img CSS rule now sets block display and zero margin while retaining width: 100%.

Estimated code review effort: 1 (Trivial) | ~2 minutes

Possibly related PRs

• oekazuma/svelte-vitals#296: Updates terminal demo styling in the same English and Japanese MDX homepage files.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly describes the homepage demo terminal spacing fix in docs and matches the main change.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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